Microbial biofilms have been demonstrated on open skin wounds, chronic leg ulcers, catheters and other medical devices. Biofilm is defined as an extensive community of sessile organisms encased within a polysaccharide-rich extracellular matrix (ECM), and associated with enhanced resistance to antimicrobial drugs. The overall hypothesis for this proposal is that the transition of C. albicans from planktonic to biofilm mode of growth is accompanied by differential expression of adhesion and glycosylation proteins. Production of these biofilm-specific proteins is expected to be closely coordinated to specific growth/functional requirements at each developmental phase. In support of this hypothesis, my preliminary studies show candidal biofilms: (i) pass through 3 developmental phase, (ii) are sensitive to the glucan synthesis inhibitor echinocandin caspofungin, (iii) express different proteins during development, (iv) show temporal expression of mannoproteins in biofilms, and (v) preliminary proteomic analyses revealed glycosylation proteins were over-expressed in biofilms. The specific aims of the current proposal are: Aim 1. Determine whether involvement of C. albicans adhesion proteins is critical to the early phase of fungal biofilm formation. In this specific aim, I will apply a proteomic approach to investigate the temporal expression of adhesion proteins during biofilm formation. In addition, isogenic strain pairs deleted for adhesion proteins will be used to confirm the role of these proteins in early biofilm formation. Aim 2. Determine the contribution of glycosylation proteins in biofilm formation. In this specific aim, I will perform proteomic analyses to determine levels of glycosylation proteins in C. albicans biofilms. Differential production of these proteins will be confirmed by Northern analyses and use of glycosylation-specific inhibitors like tunicamycin and polyoxin D. Aim 3. Determine whether administration of the echinocandin caspofungin in an in vivo model of biofilm formation will disrupt catheter-associated biofilm formation. In this specific aim, I will determine whether the disruptive effect of caspofungin observed in vitro is replicated in an in vivo guinea pig model of catheter-associated biofilms. Data from these studies may suggest novel therapeutic approaches for the prevention and treatment of skin infections related to intravascular catheters.